1. Field of the Invention
The invention relates to am image processor capable of limiting edit functions such as painting and color-converting with respect to a document.
2. Description of Related Art
A digital copy machine includes an image input terminal (IIT) for reading a document to obtain image data, an image processing system (IPS) for processing the image data, and an image output terminal (IOT) for outputting copies while driving, e.g., a laser printer, in accordance with the image data. The image input terminal, among these components, extracts image data from the document as an analog electric signal corresponding to a reflectance of light using a CCD (charge-coupled device) sensor and converts this electric signal to multi-tone digital image data. The image processing system for processing such multi-tone digital image data subjects these data to various edit operations including correction and conversion as appropriate and stores the processed data if necessary. The image output terminal outputs a dotted image by turning a laser, in the laser printer, on and off in accordance with the image data processed by the image processing system.
The thus constructed digital copy machine can subject documents to various edit processing including painting, color conversion, trimming, shifting, synthesis, reduction, and enlargement freely, to produce copies edited in diversified ways with a capability of reproducing multi-tone image data with a high resolution. Further, the image input terminal reads a document in the form of signals obtained by color-separating the document into the three primary colors, R (red), G (green), and B (blue), while the image output terminal prepares dotted toner images, each corresponding to Y (yellow), M (magenta), C (cyan), or K (black), from the above signals and outputs these toner images superimposed one upon the other to produce a color image.
However, even if the digital copy machine can edit documents freely and produce copies, in the case where all edit instructions are accepted without any restriction, inappropriate edit instructions can be followed undesirably.
For example, the paint function, which is one of the edit functions featured in the color digital copy machine, will be described. The number of optional colors is limited by the hardware, but as long as the color is one of the optional colors, a user has the freedom of selecting it. Thus, even if the specified colors form a color distribution that is loud, gloomy, out of harmony, inconsistent, or generally unfitted, the user gets no idea of how it appears until he the hard copy. As a result, he may have to change the color specification, leading to production of many copies, not only wasting resources such as copy paper, toner, electric power, and time, but also preventing the desired copy from being obtained quickly. This is often experienced by users who do not have expertise in color coordination and users who are less skillful in using.